Internet-based services are very popular and continue to multiply in number and improve in quality. For example, on-line e-mail systems can be accessed from all over the world (not simply from a LAN inside a particular organization) and can store a lifetime of e-mail correspondence. Internet search engines provide incredibly accurate responses to search queries, and can lead a user on a journey through information that is relevant and interesting to the user.
On-line services may benefit by acting in manners that are specific to particular users. For example, an e-mail application may learn a user's behavior and may filter e-mails to match that behavior. In a similar manner, search results may be targeted to explicit or inferred attributes of a user. As one example, a user may indicate that they are within a particular demographic group, and search results that are known to be relevant to that demographic group may be elevated over other search results for the user. Similarly, advertisements may be targeted to known preferences of a user, so that the user may be presented with advertisements that are more interesting and relevant to the user. In such a manner, a user may be provided with improved services and their on-line experience may improve as a result, and advertisers benefit by having better user reactions to their advertisements.
Such targeting may be difficult when delivering search results because of the issue of polysemy. In particular, a single word or group of words may have different meanings in different contexts, and it may be difficult for a system to determine the meaning that is (silently) intended by a user submitting a query. For example, the term “mole” may be used to refer to an animal or a sneaky person. And a user can enter the same search query, intend the terms in the query to have the same meaning, but have a secret intent of what they want to receive from the query. For example, a user in the winter who queries on the term “golf” may be looking for vacation destinations, while a user who queries on “golf” during the summer may be looking for local golf courses.